#define  _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
	int a = 0, b = 0, c = 0;
	while (scanf("%d%d%d", &a, &b, &c) != EOF)
	{
		if (a + b > c && c + b > a && a + c > b)
		{
			if (a == b && b == c)
				printf("Equilateral triangle!\n");
			else if (a == b || b == c || c == a)
				printf("Isosceles triangle!\n");
			else
				printf("Ordinary triangle!\n");
		}
		else
			printf("Not a triangle!\n");

		
	}
	return 0;
}